title: The role of Eag and HERG channels in cell proliferation and apoptotic cell death in SK-OV-3 ovarian cancer cell line.
abstract: BACKGROUND
  The voltage gated potassium (K+) channels Eag and HERG have been implicated in the pathogenesis of various cancers, through association with cell cycle changes and programmed cell death. The role of these channels in the onset and progression of ovarian cancer is unknown. An understanding of mechanism by which Eag and HERG channels affect cell proliferation in ovarian cancer cells is required and therefore we investigated their role in cell proliferation and their effect on the cell cycle and apoptosis of ovarian cancer cells.
  
  
  METHODS
  The presence of Eag and HERG was determined in SK-OV-3 cells using immunofluorescence and western blotting. The effect of the Eag blockers (imipramine and clofilium) and HERG blockers (E-4031 and ergtoxin) on cell proliferation was assessed using the MTS assay with further investigation of their role in the cell cycle and apoptosis determined by flow cytometry.
  
  
  RESULTS
  Eag and HERG channels were present in the cytoplasm and nuclei of SK-OV-3 cells. There was significant inhibition of proliferation of SK-OV-3 cells by imipramine (P < 0.001) and ergtoxin (P < 0.05) at 72 hours of culture. Incubation of cells with ergtoxin led to the accumulation of cells in the S and G2/M phase, while cells accumulated in S phase after incubation with E-4031, with no effect on apoptosis. Imipramine did not affect the cell cycle but increased the proportion of SK-OV-3 cells undergoing early apoptosis.
  
  
  CONCLUSIONS
  Both Eag and HERG channels are expressed in SK-OV-3 ovarian cancer cells and have a role in cell proliferation. HERG channels affect the cell cycle while Eag channels are implicated in the inhibition of apoptosis of ovarian cancer cells. The family of Eag channels may represent a new therapeutic target for the treatment of ovarian cancer.
authors.affiliation: School of Graduate Entry Medicine and Health Royal Derby Hospital, Uttoxeter Road, Derby DE22 3DT, UK. Viren.Asher@nottingham.ac.uk.
authors.forename: Viren
authors.initials: V
authors.lastname: Asher
authors.forename: Averil
authors.initials: A
authors.lastname: Warren
authors.forename: Robert
authors.initials: R
authors.lastname: Shaw
authors.forename: Heidi
authors.initials: H
authors.lastname: Sowter
authors.forename: Anish
authors.initials: A
authors.lastname: Bali
authors.forename: Raheela
authors.initials: R
authors.lastname: Khan